Nuclear Theory·nucl-th

Tuesday·December 3, 2024

20 papers—6 primary·14 cross-listed

07
[Submitted on 29 Nov 2024] (cross-list from hep-ph)
Dispersion relation for hadronic light-by-light scattering: subleading contributions
Martin Hoferichter🇨🇭 · Peter Stoffer🇨🇭 · Maximilian Zillinger🇨🇭
In this work, we present an evaluation of subleading effects in the hadronic light-by-light contribution to the anomalous magnetic moment of the muon. Using a recently derived optimized basis, we first study the matching of axial-vector contributions to short-distance constraints at the level of the scalar basis functions, finding that also the tails of the pseudoscalar poles and tensor mesons play a role. We then develop a matching strategy that allows for a combined evaluation of axial-vector and short-distance constraints, supplemented by an estimate of tensor-meson contributions based on simplified assumptions for their transition form factors. Uncertainties are primarily propagated from the axial-vector transition form factors and the variation of the matching scale, but we also consider estimates of the low-energy effect of hadronic states not explicitly included. In total, we obtain $a_{μ}^{HLbL}_{subleading} = 33.2 (7.2) \times 1 0^{- 11}$ , which in combination with previously evaluated contributions in the dispersive approach leads to $a_{μ}^{HLbL}_{total} = 101.9 (7.9) \times 1 0^{- 11}$ .
Comments:
28 pages, 7 figures; journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2412.00178 [pdf]
JHEP(2025)·57 citations
08
[Submitted on 29 Nov 2024] (cross-list from hep-ph)
Complete dispersive evaluation of the hadronic light-by-light contribution to muon $g - 2$
Martin Hoferichter🇨🇭 · Peter Stoffer🇨🇭 · Maximilian Zillinger🇨🇭
Hadronic light-by-light (HLbL) scattering defines one of the critical contributions in the Standard-Model prediction of the anomalous magnetic moment of the muon. In this Letter, we present a complete evaluation using a dispersive formalism, in which the HLbL tensor is reconstructed from its discontinuities, expressed in terms of simpler hadronic matrix elements that can be extracted from experiment. Profiting from recent developments in the determination of axial-vector transition form factors, short-distance constraints for the HLbL tensor, and the vector-vector-axial-vector correlator, we obtain $a_{μ}^{HLbL} = 101.9 (7.9) \times 1 0^{- 11}$ , which meets the precision requirements set by the final result of the Fermilab experiment.
Comments:
7 pages, 6 figures; journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2412.00190 [pdf]
PRL(2025)·32 citations
09
[Submitted on 29 Nov 2024] (cross-list from astro-ph.HE)
Dispersion relations of relativistic radiation hydrodynamics
Lorenzo Gavassino
We compute the linearised dispersion relations of shear waves, heat waves, and sound waves in relativistic ''matter+radiation'' fluids with grey absorption opacities. This is done by solving radiation hydrodynamics perturbatively in the ratio ''radiation stress-energy''/''matter stress-energy''. The resulting expressions $ω = ω (k)$ accurately describe the hydrodynamic evolution for any $k \in R$ . General features of the dynamics (e.g., covariant stability, propagation speeds, and damping of discontinuities) are argued directly from the analytic form of these dispersion relations.
Comments:
17 pages, 2 captioned figures, comments welcome!
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2412.00275 [pdf]
Astrophys.Space Sci.(2025)·4 citations
10
[Submitted on 30 Nov 2024] (cross-list from hep-ph)
Spectra of $Λ$ and $Σ$ Baryons under Screened Potential
Chandni Menapara🇮🇳 · Ajay Kumar Rai🇮🇳
The light, strange baryons have been studied through various approaches and attempted to be looked for rigorously in experiments. The screened potential has been applied to heavy baryon sector as well as meson systems in earlier works. Here, this article attempts to compare the results for linear and screened potential for light strange baryons. Also, the Regge trajectories depict the linear nature.
Comments:
11 pages, 5 figures, 2 tables, To be published in IJMPA, ICNFP-2022
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2412.00344 [pdf]
Int.J.Mod.Phys.A(2025)·0 citations
11
[Submitted on 30 Nov 2024] (cross-list from hep-ph)
Impact of nonextensivity on the transport coefficients of strongly interacting QCD matter
Dhananjay Singh🇮🇳 · Arvind Kumar🇮🇳
Tsallis nonextensive statistics is applied to study the transport coefficients of strongly interacting matter within the Polyakov chiral SU(3) quark mean field model (PCQMF). Nonextensivity is introduced within the PCQMF model through a dimensionless $q$ parameter to examine the viscous properties such as shear viscosity ( $η$ ), bulk viscosity ( $ζ_{b}$ ), and conductive properties, including electrical conductivity ( $σ_{e l}$ ) and thermal conductivity ( $κ$ ). Additionally, some key thermodynamic quantities relevant to the transport coefficients, like the speed of sound ( $c_{s q}^{2}$ ) and specific heat at constant volume ( $c_{v q}$ ), are calculated. The temperature dependence of the transport coefficients is explored through a kinetic theory approach with the relaxation time approximation. The results are compared to the extensive case where $q$ approaches 1. The nonextensive $q$ parameter is found to have a significant effect on all transport coefficients. We find that the nonextensive behaviour of the medium enhances both specific shear viscosity $η / s_{q}$ as well as conductive coefficients $σ_{e l} / T$ and $κ / T^{2}$ . In contrast, the normalised bulk viscosity $ζ_{b} / s_{q}$ is found to decrease as the nonextensivity of the medium increases. We have also studied the transport coefficients for finite values of chemical potentials. The magnitude of $η$ , $σ_{e l}$ , and $κ$ increases at lower temperatures while $ζ$ is found to decrease for systems with non-zero chemical potential.
Comments:
32 pages, 10 figures, Accepted for publication in Chinese Physics C
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2412.00444 [pdf]
CPC(2025)·1 citation
12
[Submitted on 30 Nov 2024] (cross-list from hep-ph)
Extension of the integrated hydrokinetic model to nuclear collision energies relevant for the RHIC Beam-Energy Scan program and the research program at GSI-FAIR
Musfer Adzhymambetov🇺🇦 · Yuri Sinyukov🇺🇦
The present work is devoted to developing the integrated hydrokinetic model (iHKM) for relativistic nucleus-nucleus collisions. While the previous cycle of works on this topic focused on ultra-relativistic collisions at the top RHIC and different LHC energies, the current work addresses relativistic collisions at the lower energies, specifically ranging from approximately 2 to 50 GeV per nucleon pair in the center-of-mass colliding system. In such collisions, the formation times for the initial state of dense matter can be up to three orders of magnitude longer than those in ultra-relativistic collisions. This difference reflects a fundamentally distinct nature and formation process, particularly regarding the possible stages of initial state evolution, including thermalization (which may be only partial at very low collision energies), subsequent hydrodynamic expansion, and the final transition of matter evolution into a hadronic cascade. These stages, which are fully realized in ultra-relativistic reactions, can also occur within the energy range of BES RHIC, albeit with distinct time scales. This publication not only advances the theoretical development of iHKM (referred to, if necessary, as the {\it{extended}} version of the integrated Hydrokinetic Model, iHKM{\it{e}}), but also provides examples of model applications for calculating observables. A systematic description across a wide range of experimental energies, which is preliminary yet quite satisfactory, for spectra, flow, and femtoscopy, will follow this study.
Comments:
Version published in Phys. Rev. C 112, 034906 (2025)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2412.00458 [pdf]
PRC(2025)·3 citations
13
[Submitted on 30 Nov 2024] (cross-list from nucl-ex)
Measurement of $p$ - $Ξ^{-}$ ( $p ˉ$ - $Ξ ˉ^{+}$ ) Correlation Function in Isobar and Au+Au Collisions at $s_{NN}$ = 200 GeV with the STAR Detector
Boyang Fu (for the STAR Collaboration)🇨🇳
Understanding the strong interactions between baryons, especially hyperon-nucleon ( $Y$ - $N$ ) interactions, is crucial for comprehending the equation-of-state (EoS) of the nuclear matter and inner structure of neutron star. In these proceedings, we present the measurements of $p$ - $Ξ^{-}$ ( $p ˉ$ - $Ξ ˉ^{+}$ ) correlation functions with high statistics in Isobar (Ru+Ru, Zr+Zr) and Au+Au collisions at $s_{NN}$ = 200 GeV by the STAR experiment. With the Lednický-Lyuboshitz approach, the source size and strong interaction parameters of $p$ - $Ξ^{-}$ ( $p ˉ$ - $Ξ ˉ^{+}$ ) pairs are extracted.
Comments:
4 pages, 4 figures, Proceedings of SQM 2024
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2412.00485 [pdf]
EPJ Web Conf.(2025)·2 citations
14
[Submitted on 30 Nov 2024] (cross-list from nucl-ex)
Production of Light Nuclei in Au+Au Collisions with the STAR BES-II Program
Yixuan Jin (for the STAR Collaboration)🇨🇳
The yields and ratios of light nuclei in heavy-ion collisions offer a method to distinguish between the thermal and coalescence models. Ratios such as $N_{t} \times N_{p} / N_{d}^{2}$ and $N_{^{3} He} \times N_{p} / N_{d}^{2}$ are suggested as potential probes to investigate critical phenomena within the QCD phase diagram. The significantly larger datasets from STAR BES-II compared to BES-I, combined with enhanced detector capabilities, allow for more precise measurements. In this proceeding, we present the centrality and energy dependence of transverse momentum spectra and particle yields of (anti-)proton, (anti-)deuteron, and $^{3} He$ at BES-II energies ( $s_{NN}$ = $7.7 - 27$ GeV), as well as the light nuclei to proton yield ratios and coalescence parameters $(B_{2} (d)$ and $B_{3} (^{3} He))$ .
Comments:
4 pages, 4 figures, Proceedings of Strangeness in Quark Matter 2024
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2412.00510 [pdf]
EPJ Web Conf.(2025)·2 citations
15
[Submitted on 1 Dec 2024] (cross-list from hep-ph)
Quantum thermalization of Quark-Gluon Plasma
Shile Chen🇨🇳 · Li Yan🇨🇳 · Shuzhe Shi
The thermalization of quark gluon plasma created in relativistic heavy-ion collisions is a crucial theoretical question in understanding the onset of hydrodynamics, and in a broad sense, a key step to the exploration of thermalization in isolated quantum systems. Addressing this problem theoretically, in a first principle manner, requires a real-time, non-perturbative method. To this end, we carry out a fully quantum simulation on a classical hardware, of a massive Schwinger model, which well mimics QCD as it shares the important properties such as confinement and chiral symmetry breaking. We focus on the real-time evolution of the Wigner function, namely, the two-point correlation function, which approximates quark momentum distribution. In the context of the eigenstate thermalization hypothesis and the evolution of entropy, our solution reveals the emergence of quantum thermalization in quark-gluon plasma with a strong coupling constant, while thermalization fails progressively as a consequence of the gradually increased significance of quantum many-body scar states in a more weakly coupled system. More importantly, we observe the non-trivial role of the topological vacuum in thermalization, as the thermalization properties differ dramatically in the parity-even and parity-odd components of the Wigner function.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2412.00662 [pdf]
15 citations
16
[Submitted on 1 Dec 2024] (cross-list from gr-qc)
Interacting quark matter and $f (Q)$ gravity: A new paradigm in exploring the properties of quark stars
Debadri Bhattacharjee🇮🇳 · Koushik Ballav Goswami🇮🇳 · Pradip Kumar Chattopadhyay🇮🇳
Perturbative Quantum Chromodynamics corrections and the colour superconductivity indicate that strongly interacting matter can manifest unique physical behaviours under extreme conditions. Motivated by this notion, we investigate the interior structure and properties of quark stars composed of interacting quark matter, which provides a comprehensive avenue to explore the strong interaction effects, within the framework of $f (Q)$ gravity. A unified equation of state is formulated to describe various phases of quark matter, including up-down quark matter $(2 S C)$ , strange quark matter $(2 S C + s)$ , and the Colour-Flavor Locked $(C F L)$ phase. By employing a systematic reparametrisation and rescaling, the number of degrees of freedom in the equation of state is significantly reduced. Utilising the Buchdahl-I metric ansatz and a linear $f (Q)$ functional form, $f (Q) = α_{0} + α_{1} Q$ , we derive the exact solutions of the Einstein field equations in presence of the unified interacting quark matter equation of state. For the $2 S C$ phase, we examine the properties of quark stars composed of up-down quark matter. For the $(2 S C + s)$ and $C F L$ phases, we incorporate the effects of a finite strange quark mass $(m_{s} \neq = 0)$ . The Tolman-Oppenheimer-Volkoff equations are numerically solved to determine the maximum mass-radius relations for each phase. Our results indicate that the model satisfies key physical criteria, including causality, energy conditions, and stability requirements, ensuring the viability of the configurations. Furthermore, the predicted radii for certain compact star candidates align well with observational data. The study highlights that quark stars composed of interacting quark matter within the $f (Q)$ gravity framework provide a robust and physically consistent stellar model across all considered phases.
Comments:
24 pages, 33 figures
Subjects:
General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
arXiv:
2412.00693 [pdf]
JHEAp(2026)·3 citations
17
[Submitted on 1 Dec 2024] (cross-list from quant-ph)
Quantum simulation of the phase transition of the massive Thirring model
Jia-Qi Gong🇨🇳 · Ji-Chong Yang🇨🇳
Recent advancements in quantum computing technology have enabled the study of fermionic systems at finite temperature via quantum simulations. This presents a novel approach to investigating the chiral phase transition in such systems. Among these, the quantum minimally entangled typical thermal states~(QMETTS) algorithm has recently attracted considerable interest. The massive Thirring model, which exhibits a variety of phenomena at low temperatures, includes both a chiral phase transition and a topologically non-trivial ground state. It therefore raises the intriguing question of whether its phase transition can be studied using a quantum simulation approach. In this study, the chiral phase transition of the massive Thirring model and its dual topological phase transition are studied using the QMETTS algorithm. Numerical results are obtained on a classical computer simulating circuit-based quantum computations. The results show that QMETTS is able to accurately reproduce the phase transition and thermodynamic properties of the massive Thirring model.
Comments:
upload the published version
Subjects:
Quantum Physics (quant-ph); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2412.00803 [pdf]
JHEP(2025)·4 citations
18
[Submitted on 1 Dec 2024] (cross-list from hep-lat)
Toward extracting scattering phase shift from integrated correlation functions III: coupled-channels
Peng Guo🇺🇸 · Frank X. Lee🇺🇸
The formalism developed in Refs.\cite{Guo:2023ecc,Guo:2024zal} that connects integrated correlation function of a trapped two-particle system to infinite volume scattering phase shift is further extended to coupled-channel systems in the present work. Using a trapped non-relativistic two-channel system as an example, a new relation is derived that retains the same structure as in the single channel, and has explicit dependence on the phase shifts in both channels but not on the inelasticity. The relation is illustrated by an exactly solvable coupled-channel quantum mechanical model with contact interactions. It is further validated by path integral Monte Carlo simulation of a quasi-one-dimensional model that can admit general interaction potentials. In all cases, we found rapid convergence to the infinite volume limit as the trap size is increased, even at short times, making it potentially a good candidate to overcome signal-to-noise issues in Monte Carlo applications.
Comments:
match to accepted version at PRD
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2412.00812 [pdf]
PRD(2025)·8 citations
19
[Submitted on 1 Dec 2024] (cross-list from nucl-ex)
Directed Flow of $Λ$ , $_{Λ}^{3} H$ and $_{Λ}^{4} H$ in Au+Au collisions at $s_{NN}$ = 3.2, 3.5, 3.9 and 4.5 GeV at RHIC
Junyi Han (for STAR Collaboration)🇨🇳
Studying hyper-nuclei yields and their collectivity can shed light on their production mechanism as well as the hyperon-nucleon interactions. Heavy-ion collisions from the RHIC beam energy scan phase II (BES-II) provide an unique opportunity to understand these at high baryon densities. In these proceedings, we present a systematic study on energy dependence of the directed flow ( $v_{1}$ ) for $Λ$ and hyper-nuclei ( $_{Λ}^{3} H$ , $_{Λ}^{4} H$ ) from mid-central Au+Au collisions at $s_{NN}$ = 3.2, 3.5, 3.9 and 4.5 GeV, collected by the STAR experiment with the fixed-target mode during BES-II. The rapidity (y) dependence of the hyper-nuclei $v_{1}$ is studied in mid-central collisions. The extracted $v_{1}$ slopes ( $d v_{1} / d y ∣_{y = 0}$ ) of the hyper-nuclei are positive and decrease gradually as the collision energy increases. These hyper-nuclei results are compared to that of light-nuclei including p, d, t/ $^{3} He$ and $^{4} He$ . Finally, these results are compared with a hadronic transport model including coalescence after-burner.
Comments:
4 pages, 3 figures, The proceedings of SQM2024
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2412.00871 [pdf]
EPJ Web Conf.(2025)·1 citation
20
[Submitted on 2 Dec 2024] (cross-list from hep-lat)
Nucleon charges and $σ$ -terms in lattice QCD
C. Alexandrou (Univ. of Cyprus & The Cyprus Inst.)🇨🇾 · S. Bacchio (The Cyprus Inst.)🇨🇾 · J. Finkenrath (CERN)🇨🇭 · C. Iona (Univ. of Cyprus)🇨🇾 · G. Koutsou (The Cyprus Inst.)🇨🇾 · Y. Li (Univ. of Cyprus)🇨🇾 · G. Spanoudes (Univ. of Cyprus)🇨🇾
We determine the nucleon axial, scalar and tensor charges and the nucleon $σ$ -terms using twisted mass fermions. We employ three ensembles with approximately equal physical volume of about 5.5~fm, three values of the lattice spacing, approximately 0.06~fm, 0.07~fm and 0.08~fm, and with the mass of the degenerate up and down, strange and charm quarks tuned to approximately their physical values. We compute both isovector and isoscalar charges and $σ$ -terms and their flavor decomposition including the disconnected contributions. We use the Akaike Information Criterion to evaluate systematic errors due to excited states and the continuum extrapolation. For the nucleon isovector axial charge we find $g_{A}^{u - d} = 1.250 (24)$ , in agreement with the experimental value. Moreover, we extract the nucleon $σ$ -terms and find for the light quark content $σ_{π N} = 41.9 (8.1)$ ~MeV and for the strange $σ_{s} = 30 (17)$ ~MeV.
Comments:
18 pages, 17 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2412.01535 [pdf]
PRD(2025)·40 citations

Affiliations

first authorsco-authorsvia INSPIRE